Hand held power tools are widely used by many people including professionals, craftspeople, homeowners, and artists. These power tools typically include an outer housing designed to be easily held within human hands. The housing retains an electric motor which is operable to drive a chuck of the power tool. The movements provided by various power tools include reciprocating, rotating, and orbiting patterns. The movement provided with a particular tool is dependent upon the purpose of the tool.
One purpose for which power tools may be used is the abrading of contoured surfaces. Abrading tools typically include rotating devices such as drum sanders, belt sanders, and disc sanders and orbital devices such as random orbit sanders. Each type of sander provides different benefits and limitations for different abrading tasks. For example, drum sanders are very effective for use in abrading interior curves of a work piece. While drum sanders may be used for external curves, care must be taken to avoid altering the contour of the work-piece since the shape of the abrading surface is not complementary to the shape of the work piece.
Disc sanders and orbiting sanders may also be used to abrade external curves of a work piece. The abrading surface of prior art disc sanders and orbiting sanders, however, is substantially flat. Thus, while these types of sanders are generally more controllable than drum sanders, non-conformance with the shape of the work piece results in a relatively small contact area between the abrading surface and the work piece. A small contact area focuses the effect of the abrading device on a localized area of the work piece. Thus, the contour of the work piece may be inadvertently altered.
Additionally, as the surface contact area of the abrading material is reduced, the abrading material becomes more susceptible to localized failure. Thus, an abrading sheet attached to an orbital sander may rip at the location of the abrading material which is in contact with the work piece. While the damaged area may be quite small, the entire abrading sheet may be rendered unusable.
A number of specialized accessories have been developed to assist in abrading work pieces with various contours. These accessories, however, tend to be relatively expensive. Additionally, specialized contouring devices are typically specifically designed for contours of a particular shape and size. Thus, a large number of the accessories must be maintained to allow for abrading contours of different shapes and sizes.
Other devices which may be used to abrade contoured work pieces use a resilient pad placed over a sanding plate. While the use of a pad increases the surface area of the abrading material in contact with the work piece, pads conform to only slight contours. Accordingly, contour abrading is frequently still done by hand using a piece of sand paper.
Therefore, a contour abrading device that may be used with an orbital sander that conforms the abrading material to a variety of contours would be beneficial.